Statement of the Technical Field
The present disclosure concerns generally to computing devices. More particularly, the present invention relates to implementing systems and methods for localizing signal sources using multi-pole sensors.
Description of the Related Art
Atrial Fibrillation (“AF”) is the most common heart rhythm disorder and affects 2.7 million Americans, accounting for frequent health care utilization, increased hospitalizations and increased risks of stroke, heart failure and mortality. Ectopic beats from the pulmonary veins may trigger AF, the discovery of which led to the development of a non-pharmacological ablation therapy called Pulmonary Vein (“PV”) isolation, which uses radiofrequency energy to cauterize the atrial tissue in the PV's antrum in order to terminate AF and restore sinus rhythm. Unfortunately, this therapy remains suboptimal with long-term success rates of only 40% to 60%. One of the main reasons for such unsuccessful outcomes is that it fails to eliminate AF drivers outside the PVs, and their targeted elimination is key to improving outcome after AF ablation. Detection and ablation of the rotors or foci has a very significant impact on the successful termination of AF. In animal studies where AF is induced with acetylcholine and rapid pacing, optical phase mapping of action potentials has shown that rotors outside PVs are relevant to the perpetuation of AF and should be targeted for AF ablation. Similarly, in human studies, phase maps derived from basket catheter unipolar electrograms have been used to detect rotors and foci and ablate these sites. It has been shown that ablation of rotor AF sources along with PV isolation is more durable than standalone PV isolation at preventing AF recurrence at 3 year-follow up.
However, a recent method to location rotors is based on a 64-pole basket catheter and inherits the limitations of a basket catheter. For example, the resolution is limited to the proportion of electrodes in contact with endocardium and good electrode contact at all sites on the endocardium is difficult to ensure because of irregularities in the cardiac chamber surface, so that areas crucial to the arrhythmia circuit may not be recorded. Moreover, regions such as the left atrial appendage are incompletely covered by the basket catheter. As a result, the basket catheter does not record arrhythmia substrates involving these structures. Additionally, basket catheter mapping does not permit immediate correlation of activation times to precise anatomical sites, and a Multi-Polar Diagnostic Catheter (“MPDC”) must still be manipulated to the identified site for more precise mapping and localization of the target for ablation, as well as for RF energy delivery. Basket catheters also have limited torque capabilities and limited maneuverability, which hamper correct placement, and they can abrade the endocardium.